Introduction to Impact-Based
Forecasting
Paul KuceraUCAR/COMET
9th WMO/Meteo-France RA I Tropical Cyclones Training Course
IBF input from Gerald Fleming, Chair, OPAG on PWSD; Elizabeth Webster
SAWS; Rochelle Graham, HRC; Kathy-Ann Ceasar, CIMH
Course Outline
• Introduction • Introduction to IBF• Weather Ready Nations – Barbados IBF• Idealized case studies• Development of hazard, impact, and
response matrices exercise• WRNs Case Studies Module: Impact-based
Forecast Simulations https://www.meted.ucar.edu/wrn_sims/
• Barbados Case Study• Additional resources
WMO No. 1150: https://library.wmo.int/doc_num.php?explnum_id=7901
Why move to Impact-Based
Forecasting?
Weather Forecasts
and Warnings
Impact-Based Forecast
and Warning Services
Move from
What the weather will be: - 50mm in 24 hours
- 35 knot winds
What the weather will do: - Roads flooded
- Communities cut off
Towards
Impact-Based Forecasting
Observations Impacts
Warning: Heavy rain of more than 100 mm in 24 hours is expected
So??
What does it
mean to me?
The goal is to change from this type
of forecast …
Impact Warning: 1. Orange warning for rain with a medium likelihood of significant impacts2. Yellow warning for rain with a high likelihood of minor impacts
To an Impact-based Early Warning
Forecast System
1
2
Benefits
of an
Impact
Warning
Service
• Relays a message to enable those at risk to take appropriate actions
• Improved planning for different scenarios based on different impacts
• Contains information about level of confidence in the forecast for better decision-making
• Provides post-event analysis of multi-hazard impacts to assist in planning, response and mitigation of impacts
• Coordinated process to address disaster response and preparedness
• Common situational awareness
The Case for Impact-Based
Forecasting
• Good weather forecasts or warnings are not enough:– Citizens expect information about what to do to ensure
their safety and protect their property
• Many people still lose their lives and incur socio -economic costs associated with hydrometeorological hazards – Lack of appreciation and understanding of the impacts
Why Impact-Based Forecasting?
• An accurate and timely hydrometeorological warning does not guarantee safety of life or prevent major economic disruption…
• National Meteorological and Hydrological Services work more effectively with disaster / emergency managers, public, and stakeholders– Help people understand how hazards can affect them to
ensure appropriate actions
• These can be done in two ways: – Subjective working alongside stakeholders– Objective way through developing an impact model using
vulnerability and exposure datasets as well as meteorological information
Why Impact-Based Forecasting?
Successful impact-based forecasting requires collaboration with others:• Additional necessary expertise:
– Resources and knowledge (such as demographic data, crowd-sourcing techniques, geographical information systems (GISs)
– Interoperability, and third-party data integration and usage) to deliver impact services that NMHSs cannot do on their own
Key Ideas in Impact-Based Forecast
and Warning Services
Hazard• Meteorological or hydrological element that
poses a threat– Intense or prolonged rainfall– Strong winds
Forecast Uncertainty• The limit of predictability imposed by the
nature of the atmosphere
Key Ideas in Impact-Based Forecast
and Warning Services
Exposure― Who or what may be affected in an area where a haza rd may
occur
Vulnerability― The liability of exposed human beings, their liveli hoods and
property, to suffer bad effects when affected by a hazard
Risk― The probability and magnitude of harm possible to h umans, their
livelihoods and assets because of exposure and vuln erability to a hazard
Evaluating Vulnerability
• How to identify vulnerable areas?– How to track those and adapt forecasts and
warnings?
• Location• Timing• Current Environmental Conditions
Hazard, Exposure, Vulnerability
EXPOSUREHAZARD
VULNERABILITY
Hazard, Exposure, Vulnerability =
Risk
EXPOSUREHAZARD
VULNERABILITY
RISK
Key Ideas in Impact-Based Forecast
and Warning Services
Weather Warning:―“ Strong winds are expected tonight with wind
speeds of 20m/s likely”
Impact-based Warning:―“ Strong winds are expected tonight which
may result in delays or cancellation to ferry services and keep small fishing boats tied up”
Weather Warning Services
Different types of Weather Warning
1.Warnings with fixed thresholds2.Warnings with user-defined thresholds3.Warnings with variable thresholds
Weather Warning Services
Different types of Weather Warning
1.Warnings with fixed thresholds
Saffir-Simpson Scale for strength of Tropical Cyclones / Hurricanes
Weather Warning Services
Different types of Weather Warning
2. Warnings with user-defined thresholds
Flash Flood Warning for City Authority
“50mm of rain expected during the next two hours which will cause problems with the
street drainage system and lead to flooding on the roads”
Weather Warning Services
Different types of Weather Warning
3. Warnings with variable thresholds
High Temperature Warning, different thresholds for different cities
Weather Warning Services
Different types of Weather Warning
Warnings
with fixed
thresholds
Rainfall accumulations of 30
mm to 40 mm expected
tomorrow between 1400
and 2300.
Hazard
Weather Warning Services
Different types of Weather Warning
Warnings
with user-
defined
thresholds
Heavy rain expected
tomorrow afternoon
with rainfall intensities
of 3 mm/10 mins
possible, leading to
overflow in the
drainage system
Hazard
+
Vulnerability
Weather Warning Services
Different types of Weather Warning
Warnings
with variable
thresholds
(place to
place)
Weather warning –
rainfall accumulations of
20 mm to 30 mm
expected tomorrow in
low-lying areas between
1400 and midnight, with
accumulations of 50
mm to 60 mm possible
at altitudes above 1,500
m
Hazard
+
Vulnerability
Weather Warning Services
Different types of Weather Warning
Warnings
with variable
thresholds
(time to
time)
Weather warning –
rainfall accumulations
of 15 mm to 20 mm
expected tomorrow
afternoon during rush
hour
Hazard
+
Vulnerability
Weather Warning Services
Different types of Weather Warning
Impact-
Based
Warning
Rainfall accumulations
of 20 mm to 30 mm
expected tomorrow
between 1400 and
midnight, resulting in
possible road closures
due to flooding across
the southeast
Hazard
+
Vulnerability
Risk Matrix
Likelihood/Probability Threshold
Example
Impact Threshold Example – Rain
What is your advice for rain
impacts?
Impact Threshold Example – Wind
What is your advice for wind
impacts?
The Weather Warning Risk Matrix
Benefits of using a risk matrix:• Early advisories about potential impact, well
before a significant hydrometeorological event• Update the changing expected of risk,
depending on changing exposure, vulnerability and likelihood for each forecast
The Weather Warning Risk Matrix -
Benefits
• Improved planning for different scenarios based on impacts or combinations of impacts;
• Better contingency planning (best, reasonable worst-case and most likely outcomes)
• Information about level of confidence in the forecast (a more informed risk assessment)
• New information to facilitate wider social benefits
• A comprehensive and coordinated process to address disaster response and preparedness– Meteorological services -> emergency services -> public
The Weather Warning Risk Matrix
How should the risk matrix be used?
The Weather Warning Risk Matrix -
Example
4 Days before a Tropical Cyclone arrives
X
The Weather Warning Risk Matrix -
Example
3 Days before a Tropical Cyclone arrives
X
The Weather Warning Risk Matrix -
Example
2 Days before a Tropical Cyclone arrives
X
The Weather Warning Risk Matrix -
Example
1 Day before a Tropical Cyclone arrives
X
The Weather Warning Risk Matrix -
Example
Path of Risk over many days
X
X
X
X
Assessing Risks
Are the hazards and the vulnerabilities well
known?
Are risk maps and data widely available?
Monitoring and Early Warning
Develop hazard monitoring and early
warning services
Are the right parameters being monitored?
Can accurate and timely warnings be generated?
Dissemination and Communication
Communicating risks and early warnings
Do warnings reach those at risk?
Is the warning information clear and actionable?
Response Capability
Build national and community response
capabilities
Are response plans up to date and tested?
Are people prepared and ready to react to
warnings?
Developing an Impact-based Forecast System
Developing Impact-Based Forecast
and Warning Services
• Partnerships are very important…
Stakeholders/Customers
• Who uses your forecasts?– What sectors do they represent (public, aviation,
agriculture, marine)?– What are their concerns?
• How do you learn about their needs?– What challenges do you face?– Do you have agreements in place on communicating?
• Do you receive feedback from them on your products and services?
• What information do they provide you related to evaluating vulnerability?
Developing Impact-Based Forecast
and Warning Services• Which government bodies and other stakeholders
can support impact-based forecasting?• Develop governance between parties including
steering committees and advisory groups• Establish program management - roles and
responsibilities for development, implementation, delivery
• Develop a communications strategy – what are the expected services, the respective roles of partners , and outreach activities
• Develop a plan for quality management and assurance of products and services
• Is international cooperation required?
Developing Capacity for NMHSs in
IBFWS
• What are the required competencies and skills?
• Cross-training with users on requirements and procedures
• Educating users on how to use impact-based forecast and warning services�Special Users (transport, electricity, city authorities…)�Media�Public
Example of IBF Application
• Using Multi-hazard, Impacts-based Forecast and Warning Services You Tube Video: https://www.youtube.com/watch?v=UaFFBg1opBU&t =
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Example of IBF Application
• WRNs Case Studies Module: Impact-based Forecast Simulations https://www.meted.ucar.edu/wrn_sims/
Tropical Cyclone Resources from
NCAR
• The NHC Display and Diagnostic System– http://www.hfip.org/nhc-display
• The Tropical Cyclone Guidance Project– http://hurricanes.ral.ucar.edu/